Dry containers, mainly used to transport general cargo and have a wide range of applications, take an amount of 70-80% in the total containers. Generally, there are two types of dry containers, 20 feet and 40 feet containers. In order to ensure product quality and transportation safety and the like, ISO (International Standardization Organization) issued strict provisions to general cargo containers (normally called dry container), for example: ISO 1496-1 puts forward very strict provisions about the rigidity and inner space of the general cargo container. For the container, except for the provisions in ISO, in order to satisfy special requirements for the containers, CSC (The International Convention for Safe Containers) issued corresponding provisions, and UIC (Union Internationale des Chemins de Fer), TIR (Transport International Router) issued corresponding provisions, too. A dry container generally comprises a closed structure having a door disposed at back end, and the structure generally comprises: an underframe comprising two bottom longitudinal beams, two front end bottom corner fittings and two door end bottom corner fittings respectively on both ends of the two bottom longitudinal beams, a front end bottom beam connected between the two front end bottom corner fittings, a doorsill connected between the two door end bottom corner fittings, a plurality of bottom crossbeams each connected between the two bottom longitudinal beams, and a floor laid on the bottom crossbeams; four corner pillars comprise two front end corner pillars corresponding to two front end bottom corner fittings and two door end corner pillars corresponding to two door end corner fitting; two lateral walls, each lateral wall is correspondingly connecting to the front end corner pillar at front end and connecting to back end the corner pillar at back end; front wall, connected two front end corner pillar between; a door mounted between two back end corner pillar; and a top frame comprising two top longitudinal beams which are respectively on two front end top corner fittings and two door end top corner fittings on both ends of two top longitudinal beams, a front end bottom beam connected between the two front end top corner fittings, a lintel connected between the two door end bottom corner fittings, and a top plate. According to the traditional container manufacturing technology, the container is generally manufactured as whole, that is, after all parts are assembled and welded to from a complete box, a series of subsequent processes such as sand-blasting, painting, floor mounting are performed on the whole box. In order to increase manufacturing efficiency and reduce manufacturing cost, traditional way is to improve the automation degree of the basic processes such as welding and painting by continuously increasing/improving the automation equipments. However, such way of manufacturing the box as whole is always troubled by its inherent problems: first, the automation degree of the container manufacturing is low because on one hand, transportation is difficult due to cumbersome of the assembled container, and on the other hand, after assembling of the container, any wok within the box of the container is limited by conditions of the box, thus automation is difficult; second, delivering cost of the empty containers are high, since all new containers are empty, during delivering of the empty containers from manufacturer to destination, their inner spaces are vacant and cannot be utilized, thus transportation efficiency is low, and delivering cost is high; third, stacking space is big, and stacking cost is high, because the containers occupy huge stacking space and floor area in the factory, stacking cost is higher and higher; fourth, environment pressure is high, and it is difficult to perform optimization and allocation of resources, e.g., painting on the whole assembled would have negative impacts on either environment or operation persons; fifth, factory site is limited, because to avoid the high transportation cost, manufacturing factories t have to be set up in each container demand site, so, on one hand, the possibility of pollution diffusion will be increased, and on the other hand, the optimal allocation of resources will be more difficult.